Description

The Django source has many occurrences of NotImplementedErrors raised without a message. For example, if a dev creates a class inheriting from contrib.admin.SimpleListFilter and does not provide a lookups() method, all they see from the Debug template is "NotImplementedError at /path/to/file/ No exception supplied". This, in my opinion, makes seeking help difficult for those not comfortable enough to dig through the Django source. A simple message such as "instances of SimpleListFilter must provide a lookups() method" provides instant feedback and a non-ambiguous means to seeking help if needed.

In short, my request is to have all NotImplementedError exceptions raised accompanied by a message.

I realize this change would be boring to work on, so I am more than willing to read through the patch procedures and submit a patch myself if you all find this a worthy cause. (The nature of this request may even be simple enough to send through Github)

Pull request submitted and awaiting review. 92 instances of "raise NotImplementedError" used to placehold base class methods for subclassing were given verbose may/must subclass explanations, and two instances of not-implemented features were written up as well (found in /utils/datetime.py line #67 and /utils/regex_helper.py line #95).